When a person has fallen from a vessel or otherwise finds him/herself unavoidably in the sea or other areas of open water, they are referred to as a ‘casualty’. This is due to the fact that exposure to such conditions can quickly cause numerous physical consequences that eventually may lead to the death of the person. In the absence of life-preservers, buoyancy aids or proper protection, survival limits can often be measured in minutes. Even with such aids, time is usually incredibly valuable for the survival of the person, even if they stay afloat. Too often, the delay in finding the person alive results in their subsequent death despite the best medical care available.
Professional seafarers, as well as leisure craft users, often only don life jackets at night or when conditions deteriorate. However, the majority of accidents occur when people least anticipate a problem and, even when sailing on a calm and sunny day or conducting a routine operation aboard ship, there is no guarantee that an incident will not occur which could result in a member of the crew or a passenger falling overboard. This may occur at a time when the rest of the crew are least able to respond.
Generally, life preservers themselves add very little extra visibility to an individual in the water and so a person in the water presents a very small object when viewed from rescue aircraft and boats. It is well known to sailors that large objects can readily be concealed by moderate seas and smaller objects, such as a person in a life jacket, are therefore often invisible when no more than a few metres from a vessel. In view of the problems of exposure to the elements and not being able to sustain visual contact with the casualty, a man-overboard should always be treated as a life threatening situation with the consequent emergency ‘Mayday’ response.
Emergency response can vary with location, conditions and time of day. Lifeboats are no different from any other similar sized vessel, generally offering a poor observation vantage point for a casualty as he/she rises then dips below the horizon created by every wave. Even aircraft, unless fitted with highly sensitive heat detection equipment, can find it very difficult to identify such casualties until within a few metres of their location. Yet throughout this, casualties who survive often tell of the frustration of being able to see their would-be rescuers from great distances, even though they themselves cannot be seen.
The options currently available are either complex electronic ‘alerting’ systems or bulky pieces of personal equipment, unlikely to be worn at all times. Initial cost and maintenance levels are relatively substantial and electronic components often fail when suffering the consequences of impacts, salt water and time. Electronic Position Indicator Beacons (EPIRB) will typically give a location to within a mile and GPS-enabled EPIRB to within 50 metres, provided the GPS receiver can make contact with the required satellites. In some circumstances, this could require the user to hold the unit clear of the water in order to make and maintain such satellite contact. A further problem associated with some electronic systems is that accidental actuation of transmitters in close proximity to certain aviation electronics systems has caused concern, with the result that some devices have been withdrawn from service.
Although these electronic devices can, subject to the above limitations, assist greatly with providing a general location of a casualty, they do little to enhance the visual profile of the casualty. No rescue of the casualty can begin until the search is complete, such that there is a visual acquisition of the casualty. Pyrotechnic devices and lights can assist, although they all have obvious drawbacks (such as poor to zero visibility in daylight), that have prevented them being routinely worn or carried.
Previous attempts to provide devices which will increase visibility of a user when in the water include that disclosed in, for example, U.S. Pat. No. 4,725,252. This discloses a flotation device incorporating an indicator “streamer” or band member which, before deployment, is rolled up and worn in a belt by the user. When the user jumps into the water, the streamer is deployed and then extends from under the body and head of the wearer onto the surface of the water (with airbags fitted to the overall device causing the wearer to be positioned on their backs in the water). The streamer is kept afloat on the surface by the inclusion of gas-filled chambers positioned along the length only of the streamer. There are several problems with the system. For example, if the casualty was in the water in very low wind conditions the streamer would tend to wrap around them. In rougher, windier conditions, the casualty must position themselves so as to be facing into the wind-driven spray and waves, to avoid the streamer from becoming entangled with their legs. This clearly poses an additional risk to the user and increases the likelihood of ingestion of water. Any entanglement could upset buoyancy, increasing the risk of the casualty's airway being beneath the surface of the water. In addition, there are no means included in the streamer to encourage it to form the greatest possible surface area, apart from the longitudinal chambers. Deflation of even one of these could cause the streamer to fold along its longitudinal axis and become less visible.
GB2394449 discloses a “Life Lily” in which a user is to place themselves within a central pocket which is to be surrounded by a circle of indicator material, kept afloat by radial gas-filled chambers. It is intended that the indicator material be deployed after the user has placed himself within the central pocket or “body boot”, deployment usually to occur once in the water. In fact, the pressure and volume of gas required to inflate a large area of material after immersion in water would be great and, in reality, the indicator portion would be unlikely to fully deploy across the surface of the water, especially in rough seas and/or windy weather. The material would be more likely to become entangled around the user who may find it difficult to combat this, in view of his position within the body boot. In addition, due to the circular nature of the indicator portion, the parts facing into wind and waves (even it could be fully deployed) would be likely to drift, flip or fold over the user and become entangled with him.
Therefore, there is a need to provide a simple, low-cost device which can be routinely worn by a user when aboard a boat or an aircraft crossing water and which, when deployed, greatly increases the visibility of a person in the water, without posing a significant risk of additional harm to them as the result of entanglement with the device. Such a device can also be used on land.